Aspx Property Interpolation - asp.net

I'm a bit new to .Net development, been working in Java for some time now. I have an aspx page and we need to externalize some strings to make it more flexible.
If I have a table somewhere and there is just a string sitting outside an asp tag, I can replace it so that
<th> Specific Foo String </th>
becomes
<th> <%= Strings.foo %> </th>
and everything is fine, the problem I'm running into is how do you do this kind of interpolation on an asp tag property
I tried changing
<asp:Label runat="server" ID="lblFoo" Text="Specific Foo String Entry" />
to
<asp:Label runat="server" ID="lblFoo" Text='<%= Strings.foo %> Entry' />
and
<asp:Label runat="server" ID="lblFoo" Text='<%#Eval("Strings.foo") %> Entry' />
but neither worked. Is what I'm doing not possible in the aspx file, I know that I can simulate this by rewriting their properties in the code behind, but that's a level of overhead I'd rather not deal with.
Thanks

I think you are looking to do this:
<asp:Label runat="server" id="label1" Text='<%# Strings.Foo + " Entry"%>' />
Then in your code behind (most likely in your OnPageLoad) you need to call
if(!Page.IsPostBack) Page.DataBind();
You need to be cautious however as calling DataBind on controls like textboxes or any labels that may have changed due to logic in the code behind will have their values overwritten with the bound values. Checking that you are not on a post back can help with this, but there are still gotchas.
Also note that I had to move the " Entry" text into the binding statement. If it is placed outside the last '%>' then the binding does not work and it will spit out:
<%# Strings.foo %> Entry

In the codebehind of the page you would do this:
lblFoo.Text = Strings.foo + " Entry";
A good place to put this code would be in the overriden OnLoad method but that is simply a suggestion as I am unfamiliar with your application and the life cycle needs of your page.
If you want to do all this in the aspx page then simply do this:
<span><%= Strings.foo %> Entry</span>
as a Label renders as a span anyhow.

If your objective is an HTML table of strings, then you can create either a ListView or a GridView and DataBind to that. It would save you the trouble of writing out all of your properties and will also produce the correct table tags for the data.
Without knowing more about your data, I cannot provide a detailed code snippet.

You're talking about resources. Read Basic Instincts Resources and Localization in ASP.NET 2.0 which shows you the built in resource editor, and how to use the "<%$ ... %>"-binding, or using meta:resourceKey attribute.

Related

Pass variable used in aspx page to user control

We are in ASP.Net Webforms. I come from a LAMP Stack mindset...
ASPX Code (part of it)
<asp:Content runat="server" ContentPlaceHolderID="PH_MainContent">
<h3 class="fleft">
<asp:Literal runat="server" ID="li_title" />
...
<Example:userControl runat="server" someVariable="text" otherVariable=<%=li_title.Text%> thirdVariable=<%=Items["sort"].toString()%> />
So, li_title is a literal set in the code behind, I want to reuse it later, passing it to a userControl, where it shall be displayed in a javascript. Items is page.Items. I have also tried this.li_title (which is suggested to me in Visual Studio 2015).
After reading "quite a few" very similar questions, this seem the solution. However obviously I'm missing the point. What would that be..?
You can create a public property for each variable on your user control and set them in aspx. See this for more information

ASP.NET server tags rendered in client HTML, not values?

Maybe I've forgotten how to use these, but I am going crazy trying to inject a server-side value into an HTML output. There are reasons why I am doing this inline, and not server-side, so please don't suggest that as a solution.
This code on the server side:
<asp:Label ID="Label1" runat="server" Text='<%= DateTime.Now.ToString() %>' />;
Renders as this in the client HTML sent to the browser:
<span id="Label1"> <%= DateTime.Now.ToString()></span>;
And it displays as big fat empty space, and nothing output to the interface.
If I change the ASP source to using the "#" character to define as data-binding syntax, then the rendered output to browser becomes:
<span id="Label1"></span>
EDIT:
Setting Label text was just a simplified object for the sake of asking the question. In real life, I am setting the CssClass attribute, which does not allow me to use the "wrapping" workaround some have suggested. I wanted to set a public property and have all the controls update from it dynamically on page load.
Ideally, since I already have all the controls laid out on the aspx page. Just looking to add an attribute. I wanted to have:
<asp:textbox ID='MyTxtBox1' CssClass='<% strVal1 %>' />
<asp:textbox ID='MyTxtBox2' CssClass='<% strVal1 %>' />
<asp:textbox ID='MyTxtBox3' CssClass='<% strOtherVal %>' />
<asp:textbox ID='MyTxtBox4' CssClass='<% strVal1 %>' />
Now what it looks like I need to do is repeat all my (250+) controls on the codebehind in a block of code that looks like:
MyTxtBox1.CssClass=strVal1
MyTxtBox2.CssClass=strVal1
MyTxtBox4.CssClass=strVal1
MyTxtBox3.CssClass=strOtherVal
I believe that may not work on a compiled Web Application as it's not interpreted at run-time like a C# "Web Site". However, I was able to get it to work wrapping the label around the value:
<asp:Label runat="server"><%= DateTime.Now.ToString() %></asp:Label>
Set the Label1.Text = value instead of trying to use server side attrs inside of the server control

Outputting From Resource File

So I am working on localization for a website, and I have ran into many scenarios where I need to output the localized string from the resource, such as in the following markup:
<cc1:TabPanel HeaderText="<%= Culture.Strings.labelImageA %>">
<HeaderTemplate>
<img id="ImageA" runat="server"/>
</HeaderTemplate>
<ContentTemplate>
<uc2:Charter ID="CharterA" runat="server" />
</ContentTemplate>
</cc1:TabPanel>
In the instance above, I am attempting to output form the resource Culture.Strings.labelImageA but am receiving a warning that
This is not a scriplet.Will be output as plain text
Is there an escape character I can use in the markup in order to allow this to pull from the resource file? Otherwise, I will have to jump through many hoops to set this property in the code behind.
What surely works is to use binding markup <%# %>. This, however, would probably require calling DataBind manually on your control.
I doubt there exists a simpler way.

<script> tags inside an <asp:repeater>

I'm outputting a few lines of Javascript within a Repeater control on an ASPX page. I want to use a value from my DataSource inside the script tag.
A very basic example might be:
<asp:Repeater ID="RepeaterBlah" runat="server">
<ItemTemplate>
Hello <%# DataBinder.Eval(Container.DataItem, "SomeName")%>
<script>myfunction(<%# DataBinder.Eval(Container.DataItem, "SomeNumber")%>)</script>
</ItemTemplate>
</asp:Repeater>
I'm aware that most people won't repeat script tags like this, but I am using a small snippet of code from a third-party that you can place anywhere on a page to create a Flash object. You pass it a number so it knows which image gallery to display. No problems using several on one page.
To begin with, this worked fine, although I noticed the colours in Visual Web Developer indicated that it didn't really like the <%# being used inside a <script> tag. Intellisense was going a bit nuts in the code-behind too!
So what is the correct way to pass Dataset items into a script tag?
This perhaps? (Can't quite remember if the + signs should in fact be & signs though)
<%# "<script>myfunction(" + DataBinder.Eval(Container.DataItem, "SomeNumber") + ")</script>" %>
Another alternative syntax would be the following:
<%# Eval("SomeNumber", "<script>myfunction({0});</script>") %>
This uses the optional parameter where you can supply a format string.

asp.net (4) listview gives me troubles with generating id's

i'm in a asp.net listview, in the itemtemplate.
<asp:ListView runat="server" ClientIDMode="Predictable" ClientIDRowSuffix="Texttranslations_key"ID="lvwTextitems">
This is my code in the itemtemplate:
<span runat="server" onclick="openDiv('<%= EditItemDiv.ClientID%>')" style="width: 450px;"><%# Eval("Translation")%></span>
<asp:panel runat="server" id="EditItemDiv" style="display:none">
<asp:TextBox runat="server" ID = "EditItemArea" TextMode ="MultiLine" Rows="12" Columns="50" Text="<%# Eval("Translation")%>">
</asp:TextBox>
Now i have two problems.
First the span: i want the clientID of the asp:panel in the function openDiv(), so i can create some show hide functionality.
However, i get this as result:
<span onclick="openDiv('<%= EditItemDiv.ClientID%>')" style="width: 450px;">
my code isn't seen as code, but as plain text, and i don't know why?
Second, this line gets me a runtime error (The server tag is not well formed):
<asp:TextBox runat="server" ID = "EditItemArea" TextMode ="MultiLine" Rows="12" Columns="50" Text="<%# Eval("Translation")%>">
Can somebody help me out?
ps
at first i used this code for the generation of the id's: "myid<%# Eval("Id")%>" but that didn't workout either...
ps
i'm always getting in to trouble when using the Eval and the <%# %>, so it's probably some stupid thing (i hope)
For the first part, you definitely need to be using a binding expression:
<%# EditItemDiv.ClientID %>
The <%= %> scriptlet will have no context for each item. I assume you were "paraphrasing" the syntax you say you tried, so what didn't work before?
The "server tag is not well formed" is because you are trying to use double-quotes inside double-quotes. Change the outer to single-quotes:
Text='<%# Eval("Translation")%>'>
Basically, you can't nest similar quote types. Inline script will usually demand you use double-quotes, since single-quotes have a different meaning in c#, but you can use either double or single for markup parameter quoting. The upshot is that if you need to have inline script, use single quotes to wrap the markup parameter, which frees you to use double-quotes inside it.
If you need further single quotes in the output, e.g. to render a javascript parameter, just use '. You could also use " if you wanted to render double-quotes.
OnClientClick='openDiv('EditItem(<%# Eval("something") %>');'
As stated in my comment and by jamietre to fix the binding problem you need to change the code from:
Text="<%# Eval("Translation")%>"
to
Text='<%# Eval("Translation")%>'
As for the problem with the onclick of the span, it should work as you want if you just remove the runat="server" portion. I am not sure why, but it seems that adding this causes the controls to encode the onclick property.
If you need the runat="server" on the span then I will attempt to find another solution, but there are not guarantees.

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